Evaluation of a New Zealand Tremadocian trilobite

Dionide hectori Reed, 1926, is shown on the basis of new collections from the type area in New Zealand to be a Tremadocian ceratopygide close to Hysterolenus. The species was placed in Taihungshania by Kobayashi (1941). It was provisionally retained in the Taihungshaniidae by Lu (1975) who made hectori type species of a new genus Hectoria (non Hectoria Trechmann, 1918). Ruapyge nom.nov. is proposed here for the reception of hectori. The original length/width ratio is determined by Wellman's method, with little consistency in results. Data from the strain ellipses constructed by Wellman's method are then used to calculate values for the attitude of the line of no finite longitudinal strain. The values obtained graphically do not agree with those derived from a formula given by Ramsay (1967); this contradictory situation is in need of explanation.